Felter head and agitator



Aug. 25, 1964 P. E. CARON 3,145,430 FELTER HEAD AND AGITATOR Filed Dec. 14, 1960 INVENTOR. PHILIP E. CARON BY M 4 20 United States Patent 01 fice 3,1454% Patented Aug. 25, 1 964 3,145,430 FELTER HEAD AND AGETATOR Philip E. Caron, Longview, Wash, assignor to Weyerhaeuser (Jompany, Tacoma, Wash, a corporation of Washington Filed Dec. 14, 196i Ser. No. 75,742 4 Ciaims. (til. 19155) This invention relates to a device for placing a layer of fibers on a conveyor for the production of low density fiber mats and specifically relates to an improved agitator for a felter head.

Typical systems for the production of low density fiber mats are shown in U.S. Patent 2,757,115 and U.S. Patent 2,757,150. In these systems a mixture of wood fibers and resin is evenly distributed both longitudinally and transverseiy in mat form on a vacuum conveyor belt by a felter head. The fibers are individualized and dispersed by the outlet of the feiter head, a curved screen or perforated plate. The fibers are brushed through the perforations by brushes or bristles mounted on an agitator within the felter head. The agitator, a squirrel cage rotor, also serves to prevent clogging and to maintain a fluff from which the air rushing through the perforated head carries individual fibers. This agitation also minimizes plugging of holes and the delivery of slugs of agglomerated fiber-resin masses from the holes.

The major area of agitation is around the periphery of the agitator, leaving the space in the center of the agitator adjacent the agitator shaft free of such agitation. Within this dead air space there is a tendency for the fiber-resin mixture to agglomerate into a mass which blocks further passage of fibers through this space. With fiber-resin mixtures having a resin content of or less,- a type typically used for hardboard, this tendency is not great enough to affect the even distribution of fibers to the mat. However, with resin contents greater than 5% there is a great tendency to agglomerate and eventually plug the entire space of the agitator. This is noticeable if thermoplastic resins are used. This results in a gradual diminuation of the amount of fibers going to the mat and affects the longitudinal distribution of fibers to the mat. Portions of the agglomerated mass may work loose and plug some of the perforations in the outlet. This will affect the transverse distribution of fibers to the mat.

It is, therefore, an object of this invention to produce a felter head having an even fiber distribution, even with fiber-resin mixtures having a resin content greater than 5%.

It is a further object of this invention to produce a rotor for a feltor head in which the dead air space within the rotor is eliminated.

FIGURE 1 is an isometric view of the felter head, conveyor, and mat with portions cut away to show internal structure of the felter head.

FIGURE 2 is a top plan view of the felter head with portions cut away to show internal construction of the agitator.

FEGURE 1 shows the felter head 1-? placed over a vacuum conveyor 2% upon which a fiberous mat 30 is being deposited. Felter head it} comprises a housing 40 having an inlet 41 at its upper end and a curved outlet screen or apertured plate 4-2 attached to its lower end. Journaled through bearings 43 and 44 in side walls 45 and 46 of the housing 46, is the drive shaft 51 of rotor 5d. The shaft may be driven by any convenient means.

Within housing 4-9, side plates 52 and 53 are fixably mounted to drive shaft 51. The side plates 52 and 53, having a series of holes 47 therein, are spaced from the side Walls 45 and 45 so that there will be no frictional engagement with the side walls. Each side wall has an air jet 4-9 adjacent shaft 51. Air from jets 49 blow fibers from the adjacent areas of shaft 51 through holes 47 into the agitator.

Extending between the side plates 52 and 53 are a number of brush units 60. Each of these brush units comprises a plate 61 onto which a brush 62 is mounted by a series of bolts 63. The brush 62 extends outwardly and peripherally of side plates 52 and 53, and moves in a path that coincides with screen 42. Also extending between side plates 52 and 53 and radially outwardly of shaft 51 is a tubular member 70. The tubular member and the brush units may be mounted on the side plates in any convenient manner. The tubular member encloses the space forming the major dead air space within the rotor and in its preferred form is close enough to the brush units so that the brush units will agitate the fibers adjacent tube 70.

One felter head that has been found to be operable over a Wide range of rotor speeds, air rates, and fiber rates has a rotor that is 24 inches in diameter and a tubular member that is 12 inches in diameter.

A permissible variation of the above is the use of the tubular member 70 to serve as the connecting shaft between the side plates 52 and 53 which in turn are fixably mounted on stub shafts journaled through bearings in side walls 45 and 46 of the housing 40. One of the stub shafts would in turn be driven by any convenient means.

While specific details of preferred embodiments having been set forth above, it will be apparent that many changes and modifications can be made therein without departing from the spirit of the invention. It will, therefore, be understood that what has been described herein is intended to be illustrative only and is not intended to limit the scope of the invention.

I claim:

1. A felter head comprising a housing having an inlet, side walls and a curved apertured outlet,

a rotor in said housing comprising a shaft rotatably mounted in said housing side walls and extending through said housing,

said shaft having a pair of side plates mounted thereon transversely thereof,

each of said side plates being within said housing and adjacent its respective said housing side wall,

brush units extending between and peripherally of said side plates to move in a path coinciding with said outlet, and

a tubular member extending between said side plates and surrounding said shaft and spaced radially inwardly from said brush units and substantially enclosing the dead air space surrounding said shaft.

2. The apparatus of claim 1 in which each side plate has a series of holes therein, said holes being peripherally adjacent of and radially outwardly of said tubular member, and

an air jet is mounted in each of said housing side walls in alignment with said side plate holes whereby fibers may be blown from said tubular member.

3. A felter head comprising a housing having an inlet, side walls and a curved apertured outlet,

a rotor mounted within said housing comprising a pair of aligned stub shafts rotatably mounted in said housing side walls and extending into said housing,

each of said stub shafts having a side plate mounted thereon and transversely thereof,

each of said side plates being within said housing and adjacent its respective said housing side wall,

brush units extending between and peripherally of said side plates to move in a path coinciding with said outlet, and

3 a tubular member extending between said side plates spaced radially inwardly from said brush units and substantially enclosing the dead air space extending between said stub shafts. X23 5 n i? The aPPaYatus of Claim 3 in which 5 2 738 557 Andersdne t a l. Mar. 20 each side plate has a series of holes therein, said holes 2:748:429 Clark June being peripherally adjacent of and radially outwardly 2,327,663 Clark Man 5 of said tubular member, and 2 931 07 Clark A 5, an air jet is mounted in each of said housing side Walls 2,940,134 Heritage June 14,

in alignment with said side plate holes whereby fibers 10 2,940,135 Heritage June 14,

may be blown from said tubular member. 3,056,173 Matter Oct. 2,

References Cited in the file of this patent UNITED STATES PATENTS 

1. A FELTER HEAD COMPRISING A HOUSING HAVING AN INLET, SIDE WALLS AND A CURVED APERTURED OUTLET, A ROTOR IN SAID HOUSING COMPRISING A SHAFT ROTATABLY MOUNTED IN SAID HOUSING SIDE WALLS AND EXTENDING THROUGH SAID HOUSING, SAID SHAFT HAVING A PAIR OF SIDE PLATES MOUNTED THEREON TRANSVERSELY THEREOF, EACH OF SAID SIDE PLATES BEING WITHIN SAID HOUSING AND ADJACENT ITS RESPECTIVE SAID HOUSING SIDE WALL, BRUSH UNITS EXTENDING BETWEEN AND PERIPHERALLY OF SAID SIDE PLATES TO MOVE IN A PATH COINCIDING WITH SAID OUTLET, AND A TUBULAR MEMBER EXTENDING BETWEEN SAID SIDE PLATES AND SURROUNDING SAID SHAFT AND SPACED RADIALLY INWARDLY FROM SAID BRUSH UNITS AND SUBSTANTIALLY ENCLOSING THE DEAD AIR SPACE SURROUNDING SAID SHAFT. 